Left-right asymmetry of striatal dopamine D2 receptors

Brain functions may be lateralized to the right or the left hemisphere. However, the biochemical characteristics accompanying these functions are largely unknown. To test possible lateralization of striatal dopamine D-2 receptors, we examined 18 volunteers using I-123-iodobenzamide and single photon emission tomography. The striatum-to-cerebellum D-2 binding ratio was 1.93 +/- 0.22 (mean +/- S.D.) on the right side and 1.85 +/- 0.19 on the left side. In 14 subjects, D-2 binding was higher in the right compared to the left striatum (P < 0.05). These results are supported by a mete-analysis performed on 15 studies reported in the literature. We conclude that side differences of striatal dopamine D-2 receptors exist. We propose that motor activity could be responsible for our findings. ((C) 1998 Lippincott Williams & Wilkins).